Is San Francisco tap water safe to drink?
In the latest results, every contaminant we list with a single federal limit was below that limit or action level. Lead was 4.9 ppb at the 90th percentile, below the 15 ppb action level. EPA’s goal for lead is zero. EPA lists no violations for this system. See how US tap water compares nationally.
EPA’s SDWIS record lists the lead 90th percentile for 2022–2024 as 0. SFPUC’s own report gives 4.9 ppb for the August 2024 round. We show the utility’s figure.
What’s in San Francisco tap water
Latest results from SFPUC’s 2025 report and EPA records. One row per contaminant, with the type of limit in the limit column.
| Contaminant | Result | Limit | Sampled | Source |
|---|---|---|---|---|
| LeadComes mostly from home plumbing, not from the source water. | 4.9 ppb 90th percentile of 50 home taps; none above the action level; range <1–8.8 | 15 ppbAction level · goal 0Drops to 10 ppb on Nov 1, 2027 (Lead and Copper Rule Improvements). | Aug 2024 | SFPUC 2025 Water Quality Report (San Francisco) |
| CopperFrom corrosion of household copper pipes. | 72 ppb 90th percentile of 50 home taps; none above the action level; range ND–152 | 1,300 ppbAction level · goal 1,300 | Aug 2024 | SFPUC 2025 Water Quality Report (San Francisco) |
| PFOA and PFOS (PFAS)Two “forever chemicals” with a federal limit. | Not detected 24 samples at 6 entry points; none at or above the reporting level (4 ppt) | 4.0 ppt eachLegal limit (MCL) · goal 0Utilities must comply from 2029; EPA proposed 2031 in May 2026. | Mar 2023 – Mar 2024 | EPA UCMR 5 final occurrence data (Aug 2026 release) |
| Nitrate (as N)From fertilizer runoff and septic systems. | Up to 0.4 mg/L range ND–0.4 | 10 mg/LLegal limit (MCL) · goal 10 | 2025 | SFPUC 2025 Water Quality Report (San Francisco) |
| Total trihalomethanesByproducts of disinfection. | 47 ppb Highest locational running annual average; range 12–65 | 80 ppbLegal limit (MCL) | 2025 | SFPUC 2025 Water Quality Report (San Francisco) |
| Haloacetic acids (HAA5)Byproducts of disinfection. | 37 ppb Highest locational running annual average; range 6–50 | 60 ppbLegal limit (MCL) | 2025 | SFPUC 2025 Water Quality Report (San Francisco) |
| BromateByproduct of ozone treatment. | 3.5 ppb range 1.9–4.1 | 10 ppbLegal limit (MCL) · goal 0 | 2025 | SFPUC 2025 Water Quality Report (San Francisco) |
| Chloramine (as total chlorine)Disinfectant kept in the pipes on purpose. | 2.6 mg/L Average; range <0.1–3.6 | 4.0 mg/LDisinfectant limit (MRDL) · goal 4 | 2025 | SFPUC 2025 Water Quality Report (San Francisco) |
ppb = parts per billion (µg/L), ppt = parts per trillion (ng/L). The bar shows the result against the limit (black line). Limits: EPA drinking water regulations, PFAS rule, Lead and Copper Rule Improvements. “Not detected” means below the lab’s reporting level, not zero.
EPA violations
Shown: health-based violations and everything from the last 10 years. Source: EPA SDWIS record, CA3810011, retrieved Oct 13, 2026.
How hard is San Francisco water?
SFPUC blends Hetch Hetchy reservoir water with water from its Sunol Valley and Harry Tracy treatment plants and local groundwater, so hardness differs across the city.
The utility’s figures cover the whole system. To test the hardness at your tap, strips or a drop kit take minutes.
Classes: USGS (0–60 mg/L soft, 61–120 moderately hard, 121–180 hard, above 180 very hard). 1 gpg = 17.1 mg/L as calcium carbonate. Source: SFPUC 2025 Water Quality Report (San Francisco).
What to do with these numbers
Only what the data above points to.
Lead comes from home plumbing
EPA’s goal for lead is zero. SFPUC reports that it removed all known lead service lines in the 1980s. Older faucets, lead solder and lead service lines can add lead at your tap. A filter certified to NSF/ANSI 53 for lead reduces it.
Certified to reduce lead. Lead is not necessarily in your water.
All filters compared →Chloramine taste and smell
SFPUC disinfects with chloramine on purpose, below the 4.0 mg/L limit. If you dislike the taste, look for a filter certified to NSF/ANSI 42 for chloramine. For home dialysis and aquariums it must be reduced first.
Certified to reduce chloramine.
Under-sink filters compared →Test your own water
SFPUC’s numbers come from its own sampling sites. A certified lab test of your faucet shows lead and copper from your plumbing and the chloramine level at your tap. How to test your own tap for lead, starting with your water utility.
All water tests compared →